/*

Wasmtime failure repro.

Author: Steve Williams, Advance Software

Compiled as a console app, Windows, functions as expect.
Compiled as a Windows app, fails.

*/

#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <wasm.h>
#include <wasmtime.h>

static void exit_with_error(const char *message, wasmtime_error_t *error, wasm_trap_t *trap);

#define STRLEN(x) (sizeof(x)-1)

wasm_engine_t *__engine = NULL;

wasm_engine_t *Engine_Init(bool debug_mode)
{
    // Configuring engine to support generating of DWARF info.
    // lldb can be used to debug program via GDB/JIT interface provided by wasmtime.
    wasm_config_t* wasm_config = wasm_config_new();
    wasmtime_config_debug_info_set(wasm_config, debug_mode);
    __engine = wasm_engine_new_with_config(wasm_config);
    return __engine;
}


int _export_init_fn = -1;


#if INF_DEBUG_PROBE_STANDALONE
#include <windows.h>
#include <stdio.h>

void Logf(const char *format, ...)
{
   va_list arg_list;
   va_start(arg_list, format);

   // Do the format once to get the length.
#if defined _WIN32 || defined _WIN64 /// COMPILER(MSVC)
    int len = _vscprintf(format, arg_list);
#else
    char ch;
    int len = vsnprintf(&ch, 1, format, arg_list);

    // We need to call va_end() and then va_start() again here, as the
    // contents of args is undefined after the call to vsnprintf
    // according to http://man.cx/snprintf(3)

    // Not calling va_end/va_start here happens to work on lots of systems, but fails on some systems e.g. 64 bit Linux.
    va_end(arg_list);
    va_start(arg_list, format);
#endif

   // Ensure we have enough room.
   char *tmp = malloc(len+1);

    vsprintf(tmp, format, arg_list);

    va_end(arg_list);

   MessageBoxA(NULL, tmp, "repro", MB_OK);
   free(tmp);
}
#else
#define Logf printf
#endif


bool Analyze_Exports(wasm_module_t *module)
{
  // Extract export.
  wasm_exporttype_vec_t export_types;

  wasm_module_exports(module, &export_types);

  if (export_types.size == 0)
  {
     Logf("Error : Module contains no exported functions.\n");
     return false;
  }

  // Scan for exports we're expecting.
  for (auto i = 0; i < export_types.size; ++i)
  {
     const wasm_externtype_t *etype = wasm_exporttype_type(export_types.data[i]);

     if (wasm_externtype_kind(etype) == WASM_EXTERN_FUNC)
     {
       const wasm_externtype_t *type_info = wasm_exporttype_type(export_types.data[i]);

       if (wasm_externtype_kind(type_info) == WASM_EXTERN_FUNC)
       {
         const wasm_name_t *id = wasm_exporttype_name(export_types.data[i]);

         if (!strncmp("app_init", id->data, STRLEN("app_init")))
         {
            const wasm_functype_t* func_type = wasm_externtype_as_functype_const(type_info);

            // Check parameters ...
            const wasm_valtype_vec_t *param_sig = wasm_functype_params(func_type);
            bool param_match = false;

            if (param_sig->size == 1)
            {
               if (wasm_valtype_kind(param_sig->data[0]) == WASM_I32)
                  param_match = true;
            }

            // Check return sig ...
            const wasm_valtype_vec_t *return_sig = wasm_functype_results(func_type);
            bool return_sig_match = false;

            if (return_sig->size == 1)
            {
               if (wasm_valtype_kind(return_sig->data[0]) == WASM_I32)
                  return_sig_match = true;
            }

            if  (return_sig_match && param_match)
               _export_init_fn = i;
         }
       }
     }
  }

  return _export_init_fn != -1;
}

#define INF_WASM_VEC(x) { 1, &(x) }

int main()
{
  wasm_engine_t *engine = Engine_Init(true);

  FILE* file = fopen("..\\..\\examples\\repro\\wasm\\build_d\\app.wasm", "rb");
  assert(file != NULL);
  fseek(file, 0L, SEEK_END);
  size_t file_size = ftell(file);
  fseek(file, 0L, SEEK_SET);
  wasm_byte_vec_t wasm;
  wasm_byte_vec_new_uninitialized(&wasm, file_size);
  assert(fread(wasm.data, file_size, 1, file) == 1);
  fclose(file);
  wasmtime_error_t *error = NULL;

  // Now that we've got our binary web assembly we can compile our module.
  Logf("Loaded module ... size : %d\n", file_size);

  wasm_store_t *store  = wasm_store_new(__engine);

  if (!store)
  {
     Logf("No store");
     return false;
  }

  wasm_module_t *module = store ? wasm_module_new(store, &wasm) : NULL;

  if (!module)
  {
      Logf("wasm_module_new failed.\n");
      exit(1);
  }

  wasm_byte_vec_delete(&wasm);

  if (error)
    exit_with_error("failed to compile module", error, NULL);


  // With our callback function we can now instantiate the compiled module,
  // giving us an instance we can then execute exports from. Note that
  // instantiation can trap due to execution of the `app_init` function, so we need
  // to handle that here too.
  Logf("Instantiating module...\n");
  wasm_trap_t *trap = NULL;

   wasm_extern_vec_t _imports = WASM_EMPTY_VEC;
   wasm_instance_t *instance = wasm_instance_new(store, module, &_imports, &trap);

  if (error|| trap)
    exit_with_error("failed to instantiate", error, trap);

   // Lookup our `run` export function
   Logf("Extracting export...\n");

   bool ok = Analyze_Exports(module);

   if (!ok)
   {
      Logf("Exports not as expected.\n");
      exit(1);
   }

   wasm_extern_vec_t exports;
   wasm_instance_exports(instance, &exports);
   wasm_func_t* init_fn = wasm_extern_as_func(exports.data[_export_init_fn]);

   if (!init_fn)
   {
      Logf(stderr, "Export function not as expected.\n");
      exit(1);
   }


   wasm_val_t in;
   in.kind = WASM_I32;
   in.of.i32 = 1;

   wasm_val_t out;
   out.kind = WASM_I32;
   out.of.i32 = 0;


   const wasm_val_vec_t _in = INF_WASM_VEC(in);
   wasm_val_vec_t      _out = INF_WASM_VEC(out);

   trap = wasm_func_call(init_fn, &_in, &_out);

   if (trap)
   {
      exit_with_error("Function call fail :", NULL, trap);
      exit(1);
   }


   Logf("Input: %d\nOutput: %d\n",  in.of.i32, out.of.i32);

   // TODO: Clean up

   wasm_engine_delete(engine);

   return 0;
}

static void exit_with_error(const char *message, wasmtime_error_t *error, wasm_trap_t *trap) {
  Logf(stderr, "error: %s\n", message);
  wasm_byte_vec_t error_message;
  if (error != NULL) {
    wasmtime_error_message(error, &error_message);
    wasmtime_error_delete(error);
  } else {
    wasm_trap_message(trap, &error_message);
    wasm_trap_delete(trap);
  }
  Logf("%.*s\n", (int) error_message.size, error_message.data);
  wasm_byte_vec_delete(&error_message);
  exit(1);
}


#if INF_DEBUG_PROBE_STANDALONE
#ifdef INF_DEBUG
#pragma comment(lib, "..\\..\\..\\..\\target\\debug\\wasmtime.dll.lib")
#else
#pragma comment(lib, "..\\..\\..\\..\\target\\release\\wasmtime.dll.lib")
#endif
#include <windows.h>
int  WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nShowCmd)
{
   main();
   return 0;
}
#endif